milk is full of bacterian culture which causes bad breath, so it’s only natural that you would have noticed a difference by not drinking it. the same goes with cheese, not recommend, but if you brush your teeth enough you shouldnt see a difference. try flossing too, thats where bacterias are usualy hidding, between you teeth

do you get a film on your tongue? when you brush your teeth, brush your tongue too. You can also get a tongue scraper at the drugstore, and that can get rid of bacteria that builds up on the surface of your tongue